Fluid pressure clutch with emergency screw operator

ABSTRACT

An emergency device for a pressure fluid operated double cone friction clutch, particularly as used in a ship drive system, is provided in that the pressure fluid operated parts can be mechanically moved through physical engagement in case of failure of the fluid system.

United States Patent 11 1 Szynka 1 51 Jan. 2, 1973 [s41 FLUID PRESSURECLUTCH WITH 1,360,394 11/1920 Gordon ..192/ss AA EMERGENCY SCREWOPERATOR 1,743,170 1/1930 Vail .....192/105 C 3,262,529 7/1966 Kramer..192/83 [75] Inventor: Peter Szynka, Witten, (Ruhr), Germany FOREIGNPATENTS OR APPLICATIONS Assisnee: Lohm-nn & Aktlen- 1,010,393 I H1965Great Britain ..I92/85 AB fifgf wlttenburg/Ruhr Ger- PrimaryExaminer-Benjamin W. Wyche y Assistant Examiner-Randal] Heald Filed!Mllch 1971 Attorney-Smyth, Roston & Pavitt and Ralf H. 211 App]. No.:126,927 segemmd [30] Foreign Application Priority Data [57] ABSTRACT Anemergency device for a pressure fluid operated March 25, 1970 Germany..P 20 15 501.5 double cone friction clutch particularly as used in aship drive system, is provided in that the pressure fluid [52] US. Cl...192/83, 192/85 AB, 192/70 operated parts can be mechanically movedthrough [51] InLCl ..F16d 19/00 physical engagement in case of failureof the fluid [58] Field Of Search ..l92/85 C, 85 AT, 85 AB system,

85 AA, 192/84 AA, 83,105 Q41 [56] References Cited UNITED STATES PATENTS6 Claims, 6 Drawing Figures 1,232,132 7/1917 Ward ..192/41 R A 20 T 1 kWN? PATENTEDJAH 2 ms SHEET 1 0F 6 Fig. I

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SHEET 5 BF 6 FLUID PRESSURE CLUTCH WITH EMERGENCY SCREW OPERATOR Thepresent invention relates to improvements of clutches operated normallyby pressurized fluid. The invention relates particularly to improvementsin highly elastic double cone friction clutches of the heavy duty typeas used, for example, in drive and propulsion systems for ships.

Clutches of the type referred to above, are often used to connect adriving shaft to a driven shaft. There is usually provided a clutchhousing that is coupled to the driven shaft of the particular torquetransmission system, and the housing is particularly provided with twoinside conical surfaces. A mating clutch element is disposed in andcoaxially to the housing and is comprised of two parts with outerconical surfaces. Resilient coupling connects these two parts to thedrive shaft. Thus, this two part clutch element is the driven portion ofthe resilient coupling as coupled to the drive shaft, while being thedrive part of the clutch. These two internal clutch parts are axiallymovable relative to each other for placement into and out of frictionalengagement with the housing.

In order to obtain clutch operation, one of the internal clutch parts isconnected to a cylinder and the other one to a piston moving in thatcylinder. As the interior of the cylinder chamber is pressurized, thetwo inner clutch parts are resiliently spread apart in axial direction,the fluid pressure acting against the resilient reaction of thecoupling. Upon being so spread the cone surfaces of the inner clutchelements bear against the cone surfaces of the clutch housing, therebeing friction lining interposed.

It now has to be observed that the clutch may become inoperative;particularly the fluid pressure may drop, or the fluid system may failotherwise, or the clutch operating and actuating mechanism may bedamaged. In either case, the clutch would become inoperable; the twoshafts would no longer be connected, as spring pressure forces theclutch into a disengaging position. There is then the need for providingemergency equipment which, in fact, provides emergency interconnectionbetween driving and driven parts of the clutch so that torque can betransmitted between driving and driven shafts. It is particularlydesirable to provide such an emergency or fail safe device which canreadily be installed in already existing clutches. The problem wasparticularly encountered in torque transmission systems as used for andin ships.

An emergency arrangement has been developed previously and built byassignee corporation in which the drive part of the resilient couplingfor the internal clutch element was directly, mechanically connected tothe driven part of the clutch, thus, bypassing the resilient couplingfor torque transmission. For this purpose, the clutch housing wasprovided with a special flange construction; an intennediate flange waslikewise provided especially forthis purpose and particularly on thedrive sleeve for the coupling. The two flanges were then bolted togetherto establish direct coupling between the shafts. This arrangement hadthe disadvantage that the elastic properties of the coupling within theclutch construction was no longer used and operative, as that resilientcoupling was now bypassed. Moreover, the clutch construction itselfrequired modification from existing clutch constructions, and

- cally operable and displaceable through stand-by ac- 7 putting theemergency coupling into operation required extensive assembly andinstallation procedures by the time the emergency situation arises.

It is an object of the present invention to provide an emergencymechanism in pressure fluid operated clutches which can be put intooperation readily, for example, upon loss in fluid pressure and wherebyupon completion of the emergency connection the resiliency of theresilient coupling portion of the clutch remains operative. It is aparticular object of the invention to restore frictional engagement ofthe clutch elements even after the pressure fluid has in fact droppedout. Herein, the emergency device in accordance with the invention,should not be limited to transfer of a particular torque, but the torqueto be transmitted should be adjustable. Finally, the entire emergencyequipment should be constructed in such a manner so that clutches asthey are already installed and in operation, but without such emergencydevices, may subsequently be so equipped.

In accordance with the preferred embodiment of the present invention, itis suggested to provide emergency structure for pressure fluid operatedclutches in that those parts that are normally immediately and directlyactuated by the pressure fluid are to be made mechanituating means.

For example, the clutch may be provided with par ticular parts which areresiliently coupled to the drive shaft and which are hydraulicallyspread apart for non mal operation of engagement withthe driven portion(or the drive shaft) of the clutch. Cylinder and piston type arrangementis provided accordingly and respectively connected to and part of thetwo clutch parts to be spread apart. The cylinder is now to be providedwith one or several bores respectively receiving plungers. Each plungeris normally disengaged from the piston by operation of fluid pressure,but can be manipulated externally, for example, by means of a threadedbolt or adjusting screw, pushing the plunger into the piston chamber andinto engagement with the piston. As the plunger is pushed further, thepiston is displaced and actuated within the cylinder, without pressurefluid acting on the piston surface. Therefore, the plunger simulates,e.g., normal actuation of the clutch so that all of the remainingconstruction elements of the clutch including, for example, the frictionparts and the elastic coupling remains, in fact, in the torquetransmission path.

The invention will find particular utility when practiced in double conefriction clutches. The piston and cylinder portions have annular,coaxial configuration, and plural plungers may be disposed respectivelyin plural axial bores arranged in a circle on the annular cylinder. Eachplunger is preferably operated by a threaded adjusting bolt which isnormally disengaged from the plunger and separately stored, for example,in a blind bore provided in a suitable place of the clutch construction.The plunger is preferably sealed within its receiving bore to preventleakage from the cylinder chamber into which the plunger may projectwhen used. O-rings should be used for sealing. This sealing does notprevent axial movement of the plunger in the bore.

Each'plunger and receiving bore is provided with a shoulder, and the twoshoulders engage each other to retain the plunger in the bore when actedupon by fluid pressure. In case of pressure drop requiring emergencyconnection, the plunger is lifted off the shoulder of the bore by meansof the externally applied adjusting bolt. Upon turning the bolt, theplunger will engage and actuate the piston as described.

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which is regarded as theinvention, it is believed that the invention, the objects and featuresof the invention and further objects, features and advantages thereofwill be better understood from the following description taken inconnection with the accompanying drawings in which:

FIG. 1 illustrates a longitudinal section view through a clutch improvedin accordance with the preferred embodiment of the present invention,the section plane actually being taken along line A-A of FIG.

FIG. 2 is an enlarged, partial section view in a similar plane showingdetailed features of the emergency construction in accordance with theinvention, but in stand-by position;

FIG. 3 illustrates a view similar to FIG. 2, both with operatingemergency device;

FIG. 4 is a partial section through a prior art emergency coupling;

FIG. 5 is a radial section view of the clutch shown in FIG. I; thesection plane taken along line C-C of FIG. 1 to coincide with the frontsurface of the outer left hand elastic coupling element; and

FIG. 6 illustrates a partial section view along line B B in FIG. 5.

Proceeding to the detailed description of the drawings, I referparticularly to the section view of FIGS. 1 and 2, illustrating a highlyelastic twin-cone friction clutch having a two part housing 1 and lbolted to each other, part 1' extending from a flange l6. Flange 16 isprovided for securing this driven, output portion of the clutch to thedriven shaft (not shown). The housing has two inner surfaces developedas coaxial frustocones. These inner conical surfaces correspond torespective outer cone surfaces of two axially displaceable clutch parts2 and 2', constituting the inside element of the clutch. These two conesurfaces of parts'2 and 2 are provided with friction lining 4.

The drive input of the clutch assembly as a whole is provided through asleeve 20 having a flange 21 for bolting to a corresponding flange on adrive shaft (not shown). The two part element, 2, 2, that is the driveinput proper of the clutch, is connected to sleeve or hub 20 by means ofa four part highly resilient, metalrubber-metal coupling 3. Eachcoupling part has an inner driving ring 30, an outer driven ring 3b, andrubber coupling elements 3a interposed between two rings 3b and 3c. Therings 3b collectively constitute the driven output of the resilientclutch but constitute also part of the driving input for the clutchproper. For this, respective two rings 3b are rigidly secured to one ofthe inner clutch parts, eg 2, the other two rings 3b being secured tothe other, inner clutch part 2'.

One of the rings 3a serves also as support for a cylinder 9, mountingthat cylinder on clutch part 2.

Another one of the rings 3a serves correspondingly as support for apiston 10, mounting that piston on clutch part 2. Thus, clutch parts 2and 2' are respectively secured to the annular cylinder 9 and theannular piston 10. Cylinder 9 receives piston 10 there being defined apiston chamber 11 accordingly.

Upon charging piston chamber 11 with a pressurized fluid via a conduitsystem 11a, the two displaceable clutch elements 2 and 2 are axiallydisplaced in opposite direction and against resilient reaction of theseveral rubber elements 3b in the highly resilient coupling. As aconsequence of this actuation, the cone surfaces of elements 2 and 2 areurged against the respectively mating cone surfaces of the clutchhousing to obtain frictional engagement therewith through frictionlining 4 for torque transmission. Upon depressurizing the pistonchamber, resilient reaction in coupling 3 causes the clutch todisengage. The clutch elements 2 and 2' are particularly secured to theseveral metallic outer rings 3a by means of threaded bolts 22. Thecenters of the threaded bores receiving these bolts as so placed definea circle. Additional axial bores are uniformly provided on that circle.In particular, there are bores 5a in the one coupling ring 3a that canbe seen in FIG. 5. Each bore 5a is respectively axially aligned with abore 5b in part 2, which, in turn, is aligned with a bore 5c in the nextcoupling ring 3a that supports the cylinder. A stepdown or shoulderportion Se is defined at the transition leading to bore 5d in cylinder 9in which the bore is continued. For purposes of this description, Ishall refer to a configuration of four aligned bores, 5a, 5b, 5c and 5das a bore 5 in part 2 (or to a plurality thereof), with theunderstanding that each such bore 5 is actually established by fouraligned bores establishing tubular passage through four differentelements. Such bore begins in the axial outside plane of ring 3a as seenin FIG. 5 and terminates in cylinder chamber 11. There are four suchfour-aligned bores established around the center axis of the clutch inaxis parallel relation, and in displacement around the principle axis ofthe clutch.

Each bore 5 receives a plunger 6 having also a shoulder 6a. In stand-byposition, plunger 6 is under fluid pressure in chamber 11 so that itsshoulder 60 is urged into abutment with shoulder Se, so as to retain theplunger in the bore. One end of plunger 6 is, thus, acted upon in pistonfashion so that the plunger does not interfere with the clutchoperation.

The other end 6b of a plunger 6 is somewhat receded from thecorresponding other end of bore 5. The particular bore portion 5a atthat end of bore 5 is provided with threading. As shown in FIG. 2,plunger end 6a is normally exposed, i.e., nothing acts on the plungerfrom that end when the plunger is in stand-by position. However, aprotective, short shank screw may be threaded into bore 5a for closingthe bore, but without actuation engagement for the plunger. It is, ofcourse, necessary, to prevent leakage of pressure fluid along plunger 6.In order to prevent such leakage, plunger 6 is provided with a groove,particularly in the portion of largest diameter and an O-ring 7 is'placed in that groove to provide sealing of the leakage path betweenplunger 6 and plunger 5.

Turning now to FIG. 3, there is illustrated the operational state of theclutch under emergency conditions.

For this, adjusting screws, such as 8, are threaded into threaded boreportion 5a. Upon turning a screw 8 the respective plunger 6 can beshifted within bore 5 so as to project into chamber 11 and brought intoabutment with piston 10. Thus, upon turning bolt 8, piston and cylindercan be axially shifted relative to each other, and the clutch elements 2and 2' can be correspondingly brought into engagement with the housingparts land 1'.

In principle, one bore-plunger arrangement 5-6 suffices, but in order toprevent setting up a torque about an axis transverse to the system axis,i.e., in order to prevent tilting (and binding!) of the annular piston10, plural, regularly distributed bore-plunger arrangements areprovided. In the illustrated example, four such plungers are used toshift the piston 10 in chamber 11 independently from fluid pressure. Asthe several screws 8 can be tightened to a desired degree, the

torque, as transmitted to the primary and secondary part of thisparticular clutch, is adjustable.

As can readily be seen, the emergency equipment merely needs to compriseof such actuator plungers, whose operation simulates the action of fluidpressure in the cylinder chamber, so that the clutch can be actuatedanalogously. Accordingly, the torque transmitting parts remain inoperation, and particularly the frictional interaction of parts 1, l and2, 2', as well as the resilient action of coupling 3, is not bypassed.

It is important that the adjusting screws 8 are available at all times,therefore, they are normally threadedly received in blind end bores 15as provided in the one outer ring 3a and they are maintained thereinuntil use becomes necessary.

This also leads to the point that the particular emergency equipment canbe installed in already existing clutches. As can be seen, all that isnecessary, is to provide these bores 5 in the one clutch part. Theplungers are separate pins and will be inserted accordingly. The same istrue for the adjusting screws 8. The blind bores 15, receiving theadjusting screws, are a great convenience for having the screws readilyavailable under stand-by conditions. However, these bores could bedispensed with, if there is danger of weakening structure of an alreadyexisting clutch.

In the illustrated example, the plungers traverse the cylinder and acton the front face of the piston. The relation could be reversed, for theplungers to traverse the piston and to act on the cylinder. Theessential feature is the mechanical spreading of the normally fluidpressure operated parts.

In order to evaluate the advantages offered by the invention, theconstruction as described should be contrasted with a prior artemergency structure. FIG. 4 illustrates such an emergency equipmentwhereby the primary and input side of the elastic coupling is directlyconnected to the driven output side of the clutch, e.g.,

resiliency as between rotating parts within the clutch is drasticallyreduced. There is some resiliency bolts 13 will provide, but that isalmost negligible. Also, the friction lining in the clutch is not actingany longer. Thus, this type of emergency device establishes what can bedescribed as a quasi-rigid coupling between driving and driven partsbypassing actually the principle parts of the clutch. The invention asdisclosed above, minimizes emergency intervention, the clutch remainsoperative as a whole.

The invention is not limited to the embodiments described above but allchanges and modifications thereof not constituting departures from thespirit and scope of the invention are intended to be included.

I claim:

1. A pressure operated friction clutch having a double cone, outerclutch element with two inwardly directed conical surfaces, a pair ofinner axially displaceable conical clutch elements in the outer clutchelement, respectively having conical surfaces for frictionally engagingsaid two conical surfaces, resilient means connected for biasing theinner elements into a position of disengagement from the said conicalsurfaces of the outer element;

pressure means including a pressure chamber between the two inner clutchelements, enclosed by both of them, and connected for displacing theinner elements against the resilient bias for causing the inner elementsto be frictionally coupled to the outer elements by means of saidfrictional engaging, the improvement comprising:

a plurality of axis-parallel bores in the one displaceable elementarranged around the axis and terminating in said chamber, a plurality ofplungers respectively sealingly placed in the bores of the plurality,each having a front end facing the respective other displaceable clutchelement, each plunger having a rear end externally accessible throughthe respective bore, there being retaining means in the bores forpreventing escape of the plungers towards the rear, pressure in thechamber holding the plungers against the retaining means; and

adjusting screws for selective insertion in the bores for engagement ofthe rear end of the respective plunger in the bore and for causing theplunger to disengage from the retaining means and to have its front endengage the other inner clutch element for causing both said inner clutchelements to frictionally engage the outer clutch element independentlyfrom said pressure means.

2. The improvement as in claim 1, wherein the pressure medium operatedclutch elements include an annular cylinder and piston arrangement, theplungers disposed for selective projection into the cylinder chamber forengagement with one of the piston and cylinder to obtain relativedisplacement between them.

3. The improvement as in claim 1, each of the bores and the respectiveplunger therein having annular shoulders which are mutually engaged,when the plunger is disengaged from the other clutch element.

4. The improvement as in claim 1, including additional threaded boresfor normally receiving the screws when not inserted in the bores.

retaining means include a shoulder with an annular edge of therespective bores, the plungers each having bevelled portions engagingthe edge when subjected to pressure in said chamber.

1. A pressure operated friction clutch having a double cone, outerclutch element with two inwardly directed conical surfaces, a pair ofinner axially displaceable conical clutch elements in the outer clutchelement, respectively having conical surfaces for frictionally engagingsaid two conical surfaces, resilient means connected for biasing theinner elements into a position of disengagement from the said conicalsurfaces of the outer element; pressure means including a pressurechamber between the two inner clutch elements, enclosed by both of them,and connected for displacing the inner elements against the resilientbias for causing the inner elements to be frictionally coupled to theouter elements by means of said frictional engaging, the improvementcomprising: a plurality of axis-parallel bores in the one displaceableelement arranged around the axis and terminating in said chamber, aplurality of plungers respectively sealingly placed in the bores of theplurality, each having a front end facing the respective otherdisplaceable clutch element, each plunger having a rear end externallyaccessible through the respective bore, there being retaining means inthe boreS for preventing escape of the plungers towards the rear,pressure in the chamber holding the plungers against the retainingmeans; and adjusting screws for selective insertion in the bores forengagement of the rear end of the respective plunger in the bore and forcausing the plunger to disengage from the retaining means and to haveits front end engage the other inner clutch element for causing bothsaid inner clutch elements to frictionally engage the outer clutchelement independently from said pressure means.
 2. The improvement as inclaim 1, wherein the pressure medium operated clutch elements include anannular cylinder and piston arrangement, the plungers disposed forselective projection into the cylinder chamber for engagement with oneof the piston and cylinder to obtain relative displacement between them.3. The improvement as in claim 1, each of the bores and the respectiveplunger therein having annular shoulders which are mutually engaged,when the plunger is disengaged from the other clutch element.
 4. Theimprovement as in claim 1, including additional threaded bores fornormally receiving the screws when not inserted in the bores.
 5. Theimprovement as in claim 2, the plural bores and plungers extendingaxially and the additional bores being disposed on a circle concentricto the annular piston and cylinder.
 6. The improvement as in claim 1,wherein the retaining means include a shoulder with an annular edge ofthe respective bores, the plungers each having bevelled portionsengaging the edge when subjected to pressure in said chamber.